Excavator



EXCAVATOR Filed Dec. 19, 1933 2 Sheets-Sheet 1 in V5 TO A 1M Wm 5 Y ATT ME Vs.

April 30, 1935. r-" H K E 1,999,681

EXCAVATOR Filed Dec. 19. 1933 2 Sheets-Sheet 2 Milli/17 f 24 4 ATTORNEYS.

EXCAVATOR erik Hendrik Bakker, The Hague,

Netherlands Application December 19, 1933, Serial No. 7613.066 In the Netherlands December 19, 1932 The invention relates to excavators provided with scraper buckets whichare drawn over the ground by means of suitable steel cables. Such machines, as a rule, are provided with one drag cable and one lift cable, as in the drag line; or with one drag cable and one back pull cable, as in the scraper; or with one drag cable, one back pull cable and one steering cable, as in the cable excavator according to my Dutch Patent No. 31,138. The steering cable of the excavator disclosed in that patent is provided with braking means in order to regulate the digging depth of the bucket.

During'the digging period, this bucket is drawn forward in the aforementioned machine by means.

trench has nearly or exactly reached the projected level or slope, the bucket should not be placed again in the same trench but should form a new trench beside the existing one. In order to do this, the side of the bucket must be able to dig in a horizontal direction into the side of the trench and excavate this side to the desired widthl One of the advantages of the use of the device described in this invention is to be able to dig sideways with any well known excavator bucket so that the excavation reaches the predetermined level or slope.

According to my invention it is possible to regulate the degree and direction of the lateral excavation by shifting the parallel pull cables in a longitudinal direction.

More particularly, the shifting of the two pull cables can be caused by braking any one of these its neutral position.

V Fig. 2 gives on the same scale atop view of the digging bucket during its lateral excavation.

Fig. 3 shows a perspective view of a machine with two independent drums which can be braked independently of each other.

Fig. 4 shows a form of execution of the arrangement for mutually shifting the two cable wheels.

The digging bucket i, 2, 3, is drawn forward by means of two pull cables 5 and 6, as disclosed in Fig. 1. The pill] cables are connected to the bucket atthe points i and l by a bridle and/or cable structure i, i, 8, t. The pieces I, i and t, d are of equal length, so that when the two cables 5 and 6 are drawn at the same speed, the bucket moves at this speed and digs a trench having the sides 9, Ill and II, i2.

When the cables and the bucket are drawn forward for ;a second time the cable 5 is pulled more quickly than cable 6, so that the end of the cable 6 remains a short distance behind the end of cable 5, the distance being shown in the drawings by the character 1). When this action occurs the bucket will be turned in'a horizontal plane and will take the position as shown in Fig. 2. If, therefore, the two cables 5. and t are thereafter pulled forward at the same speed, the corner 4 of the bucket will dig from its side of the original trench a strip having a width q so that a new side l3, It is formed. The continuation of this operation results in the trench being widened to the desired level surface or slope.

For this arrangement to operate in an emcient manner it is necessary that the driver of the apparatus be able to shift the two cables lengthwise at any moment and to any desired amount up to a certain maximum. Above all, he must be able to keep the cables in the desired position and to bring them back again into a neutral position during any portion of the working stroke of the machine.

In order for the engine driver to do this the present invention sets forth a simple cable operating device. The cables are setin motion by their connection to any type of winch which is provided with two independent drums. It must be possible to connect these drums in such a way that both'cables have the same speed and direction. However, even with this construction there remains a danger that due to the neglect on the part of the engine driver, only one of the cables will be wound up, while the other is left to idle, in which case the idle cable will probably be seriously damaged by the bucket running over it. This disadvantage is overcome by the arrangement set forth in Fig. 3.

The driven shaft l5 has mounted upon it two drums l6 and H which are so arranged and coupled that they may be separately and independently coupled to the shaft IE or, free, can be braked by the hand brakes it and IS. The cablesleft by the drums in order that two cams 22 and 23 can be connected about the driven shaft i and connected to the drums I6 and H. cams are so placed that in the neutral position of the bucket and cables the cams are exactly diametrically opposed. However, when the braking mechanism is applied to any one of the drums, this drum remains behind in its rotation in comparison with the other drum until the two cams meet or collide, after which the first drum is taken along by the second one. The drums are returned to their original or neutral position by uncoupling the second drum from the shaft and applying its braking mechanism until the cams are again diametrically opposed. Shock absorbers (not shown) may be used to eliminate shocks caused by the action of the cams disclosed in the drawings.

If, for practical reasons, it is impossible to use the structure set forth in Fig 3, another structure shown in Fig. 4 may be utilized which would obtain the desired efficient result. In this modified construction the pull cables are allowed to run over sheaves which are shiftable in themselves. The sheaves 2D and 2! in this modified form are placed in the frames 26 and 25, which frames are connected at 26 and 21 to the beam 28. This beam 28 is arranged so that it can turn about a pin connection 29 mounted to the block 30 so that the distance 26-29 is the same as the distance 21-29.

On the opposite ends of the frames 24, 25 there is arranged a movable'connection similar to that previously mentioned. The other ends 3| and 32 are connected to a second beam 33, which beam can turn around a pin 34 mounted in the block 35 sothat the distance 3l-34 is equalto the distance 32-34. With this structure the sheaves 20 and 2| are moved in opposite directions by turning the beam 2| around the pin 28 to the .desired amount.

These The turning of this beam 28 can be effected by any type of mechanical structure. One example is shown in Fig. 4 wherein at the end of the beam 28 at the point 36 there is connected a coupling shaft 31. Associated with this coupling member 31 is a screw spindle 38 around which turns a suitable worm wheel 39 which may be placed in motion by a worm 40. The lateral movement of the worm wheel 39 is prevented by the use of two plummer blocks 40 and 42 and suitable safety releases can be utilized for limiting the stroke or turn of the beam 28.

What I claim is:'

1. An excavator mechanism comprising in combination a digging scraper bucket capable of longitudinal and lateral movement, at least two parallel cables for pulling said digging scraper bucket, remote controlling means for varying the pulling speed of said cables in order that the digging scraper may be moved in a lateral direction while it is moving in the regular longitudinal direction and without stopping the progress of the device.

2. An excavator mechanism as set forth in claim 1 wherein said pulling cables are wound upon independent drums, said drums being independently and separately mounted upon a common shaft and braked by suitable means, saiddrums having coacting cams whereby one drum can be retarded in its rotation in' relation to the other for only one half a rotation of the drums.

3. In an excavator mechanism as set forth in claim 1, a single drum upon which both cables are wound, cable sheaves over which said cables pass to said drum and means for shifting the cables by the shifting of said cable sheaves.

4. An excavator -mechanism as set forth in claim 1, wherein said pulling cables are wound upon independent drums, said drums being independently and separately mounted upon a common shaft and braked by suitablemeans, said drums having coacting cams whereby one drum can be retarded in its rotationin relation to the other for only a part of half a rotation of the drums.

FREDERIK HENDRIK BAKKER. 

